Method of forming and assembling vacuum tube supports



Jan. 25, 1944. c. GOODALE 5 METHOD OF FORMING AND ASSEMBLIgIG VACUUMTUBE SUPPORTS Filed June a, 1940 3 Sheets-Sheet 1 h ljii IIIIIIIII INVEN TOR. LYN/V CGOODALE BY 12 W I AT ORNEY.

Jan. 25,1944. c. GOODALE METHOD OF FQRMING'AND ASSEMBLING VACUUM TUBESUPPORTS 3 Sheets-Sheet 2 Filed June 8, 1940 INVENTOR. .LYA/A/CGOODALE ATORNEY.

Jan. 25, 1944. L. c. GOODALE 2,339,350

METHOD OF FORMING ANDASSEMBLING VACUUM TUBE SUPPORTS Filed June 8, 19403 Sheets-Sheet 3 [NV EN TOR. zm/vcaoooALs ATTORNEY.

METHOD @F FORMENG ASSEBfiG vac re. s i

Ly C. Goodale, Newark, N. 3., assignor to Fad eral Telephone and adicGoration, a eor= poratlon of Delaware Application tune a, 1940,Serial'No. estate 2 Claims.

This invention relates to a method of producing and assembling vacuumtube supporting structures and is in part a continuation of my copendingapplication 'Ser. No. 244,412, filed December '7, 1938.

According to one feature of my invention I provide a novel method ofpunching a partially formed glass supporting stem to provide openings inwhich electrode supporting rods may be sealed.

According to a further feature of my invention I provide a method ofassembling an electrode supporting stem for a vacuum tube vessel inwhich the partially formed stem is first provided with perforations bypunching, the metallic supporting rods'are provided with glass beading,the rods then being inserted in the perforations with the beading withinor adjacent the perforations and the assembly is heated to seal theseparts together.

According to a still further feature of my invention, a second glassbeading is provided on v the supporting rods at a spaced point withrespect to the heading first named, and a glass truss or bracing ring isfused thereto to further strengthen the support.

In accordance with these features it is an obiect of my invention toprovide a novel method of forming an electrode supporting stem and theparts thereof.

It is a further object of my invention to pro vide a novel method ofassembling a supporting stem arrangement for vacuum tube electrodes.

A better understanding of my invention as well as other features andobjects thereof will be apparent from a particular description of apreferred embodiment thereof made in connection with the accompanyingdrawings, in which Fig. 1 illustrates the method used in punching holesin the glass stem portion,

Figs. 2, 3 and 4 illustrate a longitudinal view and alternative planviews, respectively, of a particular punched stem portion,

Fig. 5 illustrates an exploded view of the electrode stem parts beforeassembly,

Fig. 5A shows a form of tool usable for shaping the beads,

Figs. 6 and '7 illustrate the heating process for I completing thesealing. Fi '7 being a partial sectional view taken along the line 1-1of Fig. 6, and

Fig. 8 illustrates in cross-section the'completed support assembly.

Turning first to Fig. 1, the apparatus for performing the method usedfor punching holes or openings in a glass flare is shown. In thisarrangement a tube l2 with one end flared outwardly to produce a flangei3 is mounted on a supporting jig 30. The inner ring 3| of support 30 isrotatably mounted and carries with it tube 12. A plurality of markers 32are provided at spaced intervals around ring 3| in order to indicate theposition of flange l3 for the production of perforations or otheropenings therein.

' Immediately adjacent supporting jig 30 is provided a punch presshaving a lower stationary arm 34 carrying a lower cutter 35 and an uppermovable arm 36 carrying a cutter 31. Fixed on stationary arm 34 is anindicator arrangement 38 which cooperates with indicators 32 forpositioning the glass stemin the upper successive positions forpunching. Cutters 31 and 35 are arranged so as to be normally placedabove and below flange l3. Spaced from the cutters a distance equal tothe interval between indicators 32 are provided upper and lower burners39, 40, which project a needle flame against flange l3 so as to softenthe glass locally around the area to be punched. After softening theglass the ring 30 is moved a distance of one space so that the softenedglass area ispositioned between the jaws 35, "of the punch press. At thesame time the next succeeding point on the flange will be positionedunder the flame to be softened for cutting out the next opening. Cutter31 is then brought down against 35 and a small disc of glass iscutentire area.

It is clear, however, that if it is desired a plurality of points may belocally heated and a plurality of holes punched simultaneously on theentire flange may be softened and all the holes punched simultaneously.

By punching out the material in the manner above described the holes mayreadily "be provided atproperly spaced intervals and of uniform size soas to facilitate complete assembly of the tube.

In Fig. 2 a longitudinal view of flanged tube I2 is shown. Fig. 3illustrates an alternative arrangement wherein a notch I4 is punched outof the rim instead of a hole It. Fig. 4 illustrates in plan view theflange 13 of Fig. 2 with a hole ll punched therein.

In Fig. 5 is shown an exploded view illustrating the various elementsfor constructing an electrode supporting stem in accordance with myinvention. In this flgure is shown an outer cylindrical stem portion' lpreferably provided at its lower end with a flange H which is adapted toconnect with other portions of the tube envelope. Tube l2 with flange l3and holes [4, is illustrated similar to the arrangement shown in Fig. 1of the drawings. Cylinder l0, upon complete assembly is sealed to theouter edge of flange l3. Preferably a plurality of holes l4 are providedso as to provide apertures in the form of a circle. It is clear,however, that instead of holes l4 as shown, other forms of aperturessuch as notches I 4' of Fig. 3 may be provided.

, Electrode supporting rods l5 are made of any suitable metal such astungsten or molybdenum and are fused through the glass to form asubstantially vacuum tight seal. A plurality of rods l5 equal in numberto the number of openings l4 in flange l3 are provided. On each of rodsI 5 is provided a beading I! which maybe formed by fitting over the roda length of glass tubing so that it will fuse to the rod in the form ofan elongated bead. These beadings I! may be formed as follows:

The inner or small diameter portion of the bead may be formed from glasstubing as de-' scribed above. The larger or protruding portion of beadl1 designated by numeral I8 may be formed by wrapping around the smalldiameter portion of the bead lengths of cane glass to produce thedesired size extension. Tins rod may be then wiped with a graphitepaddle suchas shown at 2| in Fig. 5A provided with an opening to conformto the desired shape of the flange I8. I prefer to use a graphite paddleprovided with a V notch so that the bead will be thinner at its outeredge than at the center as illustrated in Fig. 5A.

If desired in order to provide a more rigid supporting structureadditional beads I6 may be formed on rod l5 at a point spaced from headIT. A glass ring 20. of suitable size to contact the outer surfaces ofbeads l6 when applied outside of the assembly, may be provided which maybe then sealed to beads I6 to produce an additional spacing of thestructure.

A more complete understanding of the method utilized in sealing beads l8with flange i 3 and the stem portion In also with flange I3 may be hadby reference to Figs. 6 and 7. In Fig. 6 the stem portion provided withthe punched openings in flange I3 is shown in plan view and around thisflange is shown the upper edge of tube ID. A heating of the outer edgeof the flange and upper end of tube In is achieved by means of aplurality of burners 40 arranged on a common burner rack 4| and suppliedover suitable feed lines. These burners are preferably arranged inarcuate relationship so that they will be equally spaced from the tubesupport element as assembled. A centrally supported burner arrangement42 supporting a plurality of burners 43 is provided centrally of tubel2.

In Fig. 7 the relationship of the central burner with respect to theassembled elements may be more readily perceived. In this figure thetube envelope is shown in section so as to more clearly illustrate apreferred manner of assembling the elements. In the upper portion ofFig. 7 it can be seen that rod I5 is passed through aperture l4 so thatthe bead portion thereof is adjacent to v the aperture. As thussupported the flames from burners 43 serve to quite thoroughly heat theportion of the flange adjacent the beads l8 so as to soften the glass toform the seal. Burner'rack 4| and burners 40 have been omitted for thesake of cleamess. It is understood, however, that these burners 40 areadjusted to furnish heat primarily to the upper edge of theircylindrical element l0 and the outer edge of flange IS. The left-handportion of Fig. 7 illustrates the completed tube portion after sealingtogether of the elements is completed.

While in Fig. 7 the rods l5 are shown with the flange l8 of bead 11 onthe side toward which the tube I2 extends, it i clear that if desiredthey may be supported above this flange in the manner shown in Fig. 5.

The sealing of ring 20 to beads l6 may be accomplished simultaneouslywith the sealing of rods 15 to flange l3 or subsequent thereto. Thissealing may be accomplished by means'of a central burner such as burners43 and a plurality of outer burners such as shown at 40 in Figs. 6

and 7.

An example of the electrode supporting structure completely assembledmay be seen in Fig. 8, which shows such an assembly partly in section.In this figure a symmetrical arrangement of rods is provided so thatthey define a circle.

It is clear that the supporting rods I 5 need not all be straight rodsas shown but may be oflset to provide various types of supportingarrangements. Furthermore the tubes I 0, I 2, and ring l3, need not bemade circular but may be made any other desired configuration. It isunderstood, however, that the circular form is preferable since it isgenerally much easier to produce. Also, other suitable vitreous materialthan glass may be used.

It should be distinctly understood that the description of my inventionmade in connection with the accompanying drawings is merely by way ofillustration of a preferred embodiment thereof and is not to beconsidered as the scope of my invention. What I consider to ing thecylindrical body be my invention and upon which protection is embodiedin the accompanying claims.

with a margin of the flange, which comprises forming a lass bead on eachof said rods intermediate its ends, assembling said rods within theopenings with each glass bead adjacent the margin of the contiguousopening and positionwith its upper margin contiguous to the connectingmargin of the flange, and heating said flange, beads and cylinder marginsimultaneously to seal the rods in said openings and to seal the flangemargin to the cylinder. 2. A method as set forth in claim 1, wherein theheat for sealing the beads to the flange is applied by a source of heatlocated centrally within the flange and the heat for joining the flangeto the cylinder is applied by a source of heat arrangedexternally'around the flange and cylinder. LYNN C. GOODALE.

a limitation on I desire to obtain

